The present invention relates to a device and equipment for attaining reproducable measurements and representations of the posture of a free-standing human being, wherein particularly gravity forces, exerted by the human, are transmitted, possibly asymmetrically, upon a measuring structure which includes a base plate and a stand connected to the base plate by means of one or several tension rods, carrying at least two strain gauges.
Generally speaking, devices are known in the field of orthopedics to exactly ascertain damage to the motion apparatus of a person. In order to accomplish this diagnostic data, they are acquired either by themselves or in conjunction with therapy or, for example, repeatedly, e.g. following surgery in order to ascertain progress or lack of it in the recovery and improvement in the mobility of that person. Here, one employs photography as well as X-rays. It is apparent that, in order to provide measurements which are to be compared with others (earlier ones, later ones, etc.), for purposes of evaluating such progress or lack of it, it is clear that the person must assume the some posture. For example, if the person is photographed in different phases of the therapy, then the posture much be the same or the person must be made to attempt to assume the same posture, in order to provide comparable results. However, "same" in this context must be objectivized.
Here then, it was known to provide a structure in which a standing plate is supported by at least two measuring points. These "points" are constructed either as compression sensors or strain gauges, or the like. This known structure, however, is disadvantaged by the fact that a balanced position of a person is attainable only in a frontal plane, from left to right, but not, at the same time, in the sagittal plane. Hence, this known structure does not permit a reproducable centering of the posture of the human being with reference to a point. Moreover, for measuring imbalance, just in one plane, one needs at least two measuring points. In addition, the known structure is disadvantaged by the fact that owing to the direct mounting of the standing plate on the measuring elements, there is a fairly high susceptibility to equipment damage. Also, it was found that rather expensive temperature compensated amplifiers, operating with carrier frequency modulation, have to be used.
An improved device has become known through the German printed patent application P 33 01 864 (see also Canadian Pat. No. 1,227,632). Here, a particular advantageous example includes two parallel plates, namely a base plate and a stand plate, spaced apart from each other and held in position through a bending rod. Strain gauges are affixed to that rod and upon tilting of the stand plate, the rod bends and the gauges, and electrical amplifiers respond. Bending, of course, is the result of an unbalanced posture, not just in the frontal, but also in the sagittal plane. Indeed, this is a definite improvement over the earlier art.
It is also known that incorrect postures result, for example, from different length of the legs of the person, or because of a oblique position of the pelvis. These defects can be corrected through, for example, orthopedic shoes with differently thick soles, or different thick inserts. However, it can readily seen that ascertaining the degree of sole thickness or of the thickness of the insert is rather cumbersome if the above-mentioned device is used, even in the improved version. Moreover, this method is not only cumbersome but also not too accurate. The procedure involves basically the insertion of supplemental standardized plates under the foot on that side which is to be lifted for any reason. The number of these plates added to that side simply is determined by the condition to be compensated. Of course, this requires that the patient, again, has to be checked afterwards; possibly again and again.
U.S. Pat. Nos. 4,370,039 and 4,639,107 disclose a method and equipment which is traded under the mark "Optimetric", and being provided for replacing X-raying. This method is characterized by the fact that a bundle of horizontally running lines are projected obliquely from above upon the patient. In a rather simple manner, un-evennesses in the surface show readily as deflections of the line projections as reflected by the body of the patient. For purposes of comparison, the doctor will make a picture before, as well as after a therapeutic session, and then compares the two pictures. These references are mentioned here only for completion. The present invention is applicable to that equipment, for objectively ascertaining a correct posture prior to the particular measurements by that apparatus.